I recently bought an 03 mach/auto with some mods. The previous owner installed 4:10's, bassani offrd x/c back, ported manifold, c&l intake and mass air and suspension. He had the car tuned a year ago (professionally) and had 3:55 gears at the time, but never had it retuned for the 410's. Now the speedo is about 8-10mph off and I want to correct it with the supplied predator that was initially used by the installer. Can I go into the tire height setting and make the change without screwing up the tune or do i have to take it back to the shop where he had it done? Thx
